Flashlight lock-off switch



Jan, 10, 1967 D. c. GRAY ETAL 3,297,840

FLASHLIGHT LOCKOFF SWITCH Filed June 18, 1965 ATTO NEY/ United States Patent Ofitice Doring, Carbide This invention relates to an improved flashlight and more particularly to novel switching means for positively opening and closing the electrical circuit between the head lamp of the flashlight and the cells and in addition has as its principal object to provide a relatively inexpensive flashlight locking switch having a minimum number of arts.

p In accordance with the invention, the novel feature of the improved flashlight of the invention comprises a unitary contact strip secured to the switch slide. The contact strip is provided with a detent end tab which rests in a slot in the flashlight casing generally if the casing is of metal and in a detent provided in the wear plate if the casing is entirely of plastic.

One such flashlight of the latter type is disclosed in Us. Patent No. 3,261,972 issued July 19, 1966, the assignee of the instant application also being the assignee of the above-noted application. In this copending application an elongated arcuate shaped metallic wear plate is disclosed to be fixedly disposed internally in the vicinity of the switch slide. Such construction ensures long service life of the flashlight since the rubbing action of the contact strip is directed against the metal wear plate rather than the plastic casing.

' The invention will now be described in greater detail with reference to the embodiments thereof shown by way of example on the accompanying drawings, wherein:

FIGURE 1 is a view in side elevation, broken away in part to illustrate the details of construction;

FIGURE 2 is an enlarged fragmentary view in side elevation of the main portions of the locking switch of the invention;

FIGURE 3 is a plan view of the contact strip shown in FIGURES 1 and 2;

FIGURE 4 is a side view of the UR-E 3;

FIGURE 5 is a side view of a modified contact strip for use in a flashlight having a plastic casing; and

FIGURE 6 is an enlarged fragmentary view of the detent tab of the modified contact strip of FIGURE 5.

Referring now to the drawing and particularly to FIG- URES 1, 2 and 3 the improved flashlight of the invention is generally identified by the numeral 10 and the lens cover or head is denoted as 12. The flashlight 16 is basically of conventional construction save for the novel feature of the locking switch 14, as best shown in FIGURE 2. The flashlight casing or tube 16 may be of metal (as shown in the drawing) or it may be of a plastic construction such as polyethylene, polypropylene and the like. As shown in FIGURE 1, the casing 16 may be provided with transverse ribs 18 formed integrally therewith for aiding the user in positively gripping the flashlight 10. The front end of the flashlight casing 16 is denoted as 20 and it terminates in the usual externally screw-threaded neck 22. Lamp 24 is positioned within the lamp base and retainer 26 and its associated contact shell 27, and the batteries 28 and 30 are urged into cell to cell connection and into engagement with the lamp base and retainer 26 by means of a standard rear compression spring (not shown) disposed between the battery 30 and the rear portion 31 of the flashlight 10. The reflector for the lamp 24 is illustrated at 29.

The slide contact strip 32 is made of a long, thin. eleccontact strip of FIG- 3,297,840 Patented Jan. 10, 1967 trically conductive material such as spring brass, bronze, plated steel or the like, and it has distinctive features disposed along its length. As best shown in FIGURE 2, a housing or switch slide 34 is disposed through a guide hole 36 in the casing 16 and is suitably secured to the slide contact strip 32 by means of a conventional rivet fastener 38 or other equivalent fasteners, such as, for instance, machine screws and the like.

Preferably, a wear plate 40 composed of relatively harder material than that of the casing 16 is fixedly secured to the casing 16 in the region about the guide hole 36. Deflectable ears 42 and 44 are suitably provided for fastening the wear plate 40 to the flashlight casing 16. These cars 42 and 44 are bent about the end edges 46 and 48 of the guide hole 36. The wear plate 40 provides a hard bearing surface between the movable slide contact strip 32 and the generally softer flashlight casing 16 and in the preferred embodiment of the invention which employs the wear plate, it is provided with a slot 50 for the unique detent tab 52 of the slide contact strip 32. This detent tab 52 of the strip 32 is preferably integrally formed from same and is bent at an angle toward the casing 16. The tab 52 preferably makes an angle of about with the strip 32 and as shown in FIGURE 2, the locking slide switch 14 is in the off or open circuit position. To move the switch 14 to the on or closed circuit position, a free floating switch button 54 is suitably depressed against a hump or raised portion 56 in the contact strip 32 thereby disengaging the detent tab 52 from the slot 50. When the detent tab 52 is released from the slot 50, the contact strip 32 is free to be moved forward to complete the circuit. The switch button 54 is suitably biased against cooperating shoulders 55 and 57, respectively of the switch slide 34 and of the switch button 54. It should be noted that another slot can similarly be provided in the wear plate to provide a positive lock-on position.

FIGURE 3 illustrates in plan view the slide contact strip 32 of FIGURES 1 and 2. As shown therein and in FIGURES 1 and 2, another suitable hump or dimpled portion 58 ensures that the front free end 60 of the slide contact strip 32 maintains contact with the contact shell 27 during operation as when the electrical circuit is closed.

In operation, the lock-off switch 14 of the invention is normally in the off or open-circuitposition. In order to activate the switch 14 and put it into an on or closedcircuit position, the switch button 54 is first depressed to release the detent tab 52 from the slot 50 of the wear plate 40. When depressing the switch button 54, which in turn engages the raised portion or dimple 56 the depressing of a portion of the contact strip 32 automatically releases the detent tab 52 from its locking place in the slot 50 of wear plate 41 The contact strip 32 now being free to translate is slidably moved to a forwardly position by means of the switch slide or housing 34 which is suitably guided by the guide hole 36 in the casing 16. When the front end 60 of the contact strip 32 makes contact with the contact shell 27, the switch 14 is then in the on or closed-circuit position.

The circuitry is composed of the lamp, lamp base and retainer and associated contact shell, batteries or cells in series, conductive casing in contact with rear cell, contact strip in contact with casing and finally the contact strip contacting the contact shell. In putting the switch 14 into the 01f or open-circuit position, the switch slide or housing 34 is merely longitudinally translated back to its former position until the detent tab 52 of the contact strip 32 engages the slot 50 of wear plate 40 so as to positively lock-01f the switch. Thus, the front end 60 of the contact strip 32 is disengaged from being in contact with the contact shell 27. The electrical circuit is therefore broken 3 and the switch 14 is in the off or open-circuit position.

In FIGURES 5 and 6, a modified contact strip 62 is illustrated. This contact strip 62 is designed for use in the flashlight of the invention embodying a plastic casing. Since the movable contact strip 62 must make contact with the conventional metal sleeve and spring assembly (not shown) at the rear end or portion of the casing, the contact strip 62 must extend about the full length of the flashlight casing. However, a cantilevered finger 63 having a detent tab 64 functions in the same manner as the detent tab 52 of contact strip 32. In the contact strip 62, the finger 63 and associated detent tab 64 is suitably punched from the strip 62 so as to leave one side thereof firmly attached to the strip 62. This side is noted to be the front end 66 of the finger 63. Dimple 68 functions like dimple 58 and dimple 70 makes contact at the rear portion of the flashlight casing with the metal sleeve and 1spring assembly in order to complete the electrical circuit cop.

Thus, by means of the detent tab in the contact strip of the locking switch assembly, a structure is provided which positively opens and closes the electrical circuit of the flashlight. This locking switch 14 is noted to contain fewer elements than locking switches heretofore generally available and, accordingly, such switch and improved flashlight can be manufactured at lower cost. The switch of the invention provides a positive lock-off feature which is achieved by the engagement of a detent tab in .a slot or slots (should a look-on slot be provided) of the wear plate or casing should no wear plate be utilized. Note that when the wear plate is not used, the slot or slots are provided in the flashlight casing. For such a construction, it is desirable to extend the body portion of the locking switch assembly or switch slide 34 so as to conceal the slot or slots. In lieu of a slot, other suitable means such as a notch scored on the inside of the casing can function as the catch or locking means for the detent tab. In this regard, a dimple or similar protuberance on the inside of the casing could also serve as a catch. A catch in order to function properly must provide on one hand for the locking of the detent tab and on the other hand for the smooth transitional surface over which the detent tab can ride when the switch is alternately switched on and off.

It is to be understood that many changes and modifications in the details of construction of the flashlight herein described will occur to those skilled in the art and may be resorted to without departing from the spirit and scope of the invention.

What is claimed is:

1. A switch for a flashlight having a casing provided with an opening therein, comprising a switch slide slidably mounted on the outside of said casing between an on and off position, a resilient conductive contact strip mounted on the switch slide but residing on the inside of said casing and being movable with said switch slide and guided by said opening, a switch buttonfree floating and being biased against shoulders forming an opening in said switch slide by means of said contact strip, said switch button being biased by the engagement of a portion of said contact strip with said switch button; said contact strip comprising a detent tab adjacent to said portion of said contact strip which is in engagement with said switch button and said detent tab being engageable with cooperable detent receiving means within said casing whereby pressing said switch button downwardly releases said detent tab from said cooperable deten I6- ceiving means and permits said switch slide to be movable to an on posit-ion wherein said con-tact strip is longitudinally moved to engage a cooperative contact member.

2. The flashlight switch of claim 1 wherein second cooperable detent receiving means is provided within said casing for receiving said detent tab of said contact strip when said contact strip is forwardly disposed and said switch slide is in the on position.

3. The flashlight switch of claim 1 wherein said cooperable detent receiving means is provided on a wear plate disposed about said opening on the inside of said casing.

4. The flashlight switch of claim 3 wherein second cooperable detent receiving means is provided on said wear plate for receiving said detent tab of said contact strip when said contact strip is forwardly disposed and said sw-itch slide is in the on position.

5. In a portable hand lantern, comprising the combination of a hand lamp casing embodying a hollow conduit having an opening therein, said conduit constituting a handle adapted to contain batteries, a lamp being disposed within a lamp retainer and base and a cooperable contact shell, and a forwardly facing reflector disposed between said lamp and said cooperable contact shell, and switching means for said hand lantern, the improvement which comprises a switch slide slidably mounted on the outside of said conduit between an on and off position, a resilient conductive contact strip mounted on the switch slide but residing on the inside of said conduit and being movable with said switch slide and guided by said opening in said conduit, a free floating switch button biased against shoulders forming an opening in said switch slide by means of said contact strip, said switch button being biased by the engagement of a portion of said contact strip with said switch button; said contact strip comprising a detent tab adjacent to said portion of said contact strip which is in engagement with said switch button and said detent tab being engageable with cooperable detent receiving means within said conduit whereby pressing said switch button downwardly releases said detent tab from said cooperable detent receiving means and permits said switch slide of said switching means to :be movable to an on position wherein said contact strip is longitudinally moved to engage said contact shell.

6. The improvement of claim 5 wherein said cooperable detent receiving means is provided on a wear plate disposed about said opening on the inside of said conduit.

7. The improvement of claim 6 wherein second cooperable detent receiving means is provided on said wear plate for receiving said detent tab of said contact strip when said contact strip is forwardly disposed and said switch slide is in the on position.

8. The improvement of claim 6 wherein said conduit is non-conductive and said contact strip is always in electrical contact with the bottom terminal portion of said rearwardly disposed battery.

References Cited by the Examiner UNITED STATES PATENTS 1,436,340 11/1922 Gallagher ZOO--60 BERNARD A. GILHEANY, Primary Examiner.

H. A, LEWITTER, Assistant Examiner. 

1. A SWITCH FOR A FLASHLIGHT HAVING A CASING PROVIDED WITH AN OPENING THEREIN, COMPRISING A SWITCH SLIDE SLIDABLY MOUNTED ON THE OUTSIDE OF SAID CASING BETWEEN AN ON AND OFF POSITION, A RESILIENT CONDUCTIVE CONTACT STRIP MOUNTED ON THE SWITCH SLIDE BUT RESIDING ON THE INSIDE OF SAID CASING AND BEING MOVABLE WITH SAID SWITCH SLIDE AND GUIDED BY SAID OPENING, A SWITCH BUTTON FREE FLOATING AND BEING BIASED AGAINST SHOULDERS FORMING AN OPENING IN SAID SWITCH SLIDE BY MEANS OF SAID CONTACT STRIP, SAID SWITCH BUTTON BEING BIASED BY THE ENGAGEMENT OF A PORTION OF SAID CONTACT STRIP WITH SAID SWITCH BUTTON; SAID CONTACT STRIP COMPRISING A DETENT TAB ADJACENT TO SAID PORTION OF SAID CONTACT STRIP WHICH IS IN ENGAGEMENT WITH SAID SWITCH BUTTON AND SAID DETENT TAB BEING ENGAGEABLE WITH COOPERABLE DETENT RECEIVING MEANS WITH SAID CASING WHEREBY PRESSING SAID SWITCH BUTTON DOWNWARDLY RELEASES SAID DETENT TAB FROM SAID COOPERABLE DETENT RECEIVING MEANS AND PERMITS SAID SWITCH SLIDE TO BE MOVABLE TO AN ON POSITION WHEREIN SAID CONTACT STRIP IS LONGITUDINALLY MOVED TO ENGAGE A COOPERATIVE CONTACT MEMBER. 